通过浸渍法在活性炭上负载硝酸铁、过硫酸盐对活性炭进行改性,以此为催化剂催化过氧化氢氧化去除有机废水橙黄Ⅳ.研究了体系pH值、催化剂投加量、反应温度、橙黄Ⅳ以及H2O2初始浓度等因素对橙黄Ⅳ去除率的影响,并对该催化剂重复使用性能进行测试.结果表明,硫的掺杂可以显著地提高硝酸铁改性活性炭的催化活性.目标物的初始浓度越低,反应速率越快,该反应遵循二级反应动力学,反应的活化能Ea为68.19 kJ.mol-1.在pH值2.4~9.1的范围内,催化剂均能有效地对橙黄Ⅳ进行催化降解.随着催化剂投量的增加,橙黄Ⅳ的去除效率明显提高,催化剂重复使用6次仍具有较好的催化活性,去除率仍可达到70%以上.自由基实验表明该氧化体系主要遵循自由基作用机制.
This study was designed to investigate the catalytic oxidation performance of modified GAC by Fe(NO3)3and(NH4)2S2O8in the process of H2 O2.The effect of the initial concentration of H2 O2,initial dye concentration,catalyst dosage,initial pH and temperature on the reaction was discussed.The results show that the catalyst of Fe/S/GAC has a better catalytic reactivity to decompose Orange IV compared with that of Fe/GAC.The catalyst could decompose H2 O2 to degrade Orange Ⅳ effectively at pH 2.4-9.1.The removal rate of Orange Ⅳ increased with the increase of catalyst dosage.With the decrease of dye concentration,the reaction rate became faster,this reaction followed the second-order reaction kinetics with activation energy(Ea)of 68.19 kJ·mol-1.Reuse of catalyst did not decrease the removal rate.Orange Ⅳ degradation mainly followed ·OH mechanism.